SwiftUI how to prevent view to reload whole body

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SwfitUI has a pattern for this. It needs to conform custom view to Equatable protocol

struct CustomView: View, Equatable {

    static func == (lhs: CustomView, rhs: CustomView) -> Bool {
        // << return yes on view properties which identifies that the
        // view is equal and should not be refreshed (ie. `body` is not rebuilt)
    }
...

and in place of construction add modifier .equatable(), like

var body: some View {
      CustomView().equatable()
}

yes, new value of CustomView will be constructed every time as superview refreshing (so don’t make init heavy), but body will be called only if newly constructed view is not equal of previously constructed

Finally, it is seen that it is very useful to break UI hierarchy to many views, it would allow to optimise refresh a lot (but not only good design, maintainability, reusability, etc. :^) ).

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